/*! \page Optimize_methodDoc Optimize method

Keyword: OPTIMIZE

\section description Description

On a fixed sample set, optimize one of a number of objective functions with respect to the wave function parameters.  Note that energy optimization using this method is typically not efficient; either OPTIMIZE2 or LINEAR should be used in that case.

This method is most useful to perform rough variance optimization of a Jastrow factor prior either to performing a DMC calculation or more refined optimization using OPTIMIZE2 or LINEAR.

\section options Options

\subsection reqopt Required 

<table>
<tr> <td> <b>Option</b> <td> <b>Type</b> <td> <b>Description</b>
</table>

\subsection optopt Optional

<table>
<tr> <td> <b>Option</b> <td> <b>Type</b> <td> <b> Default </b> 
     <td> <b>Description</b>
<tr> <td> NCONFIG  <td> Integer <td> 2048  <td>  Number of configurations per processor.  By default, QWalk will choose a total number close to 2048, spread across all processors.
<tr> <td> READCONFIG <td> String <td> <td> Read configurations from a file.  By default, QWalk will generate the configurations automatically.
<tr> <td> ITERATIONS  <td> Integer <td> 30 
     <td>  Number of optimization iterations. 30 is a pretty good default,
     which should work except in special cases.
<tr> <td> EREF  <td> Float <td> special <td> A best guess at the optimized energy.  If you don't put this keyword, QWalk will make a good guess at the proper value, which should be good enough unless the system is rather large.
<tr> <td> WFOUTPUT <td> String <td>  runid.wfout 
     <td> Choose the filename to place an input deck for the final 
wavefunction and intermediate ones as the optimization
continues.
</table>

\subsection expopt Experimental 
<table>
<tr> <td> <b>Option</b> <td> <b>Type</b> <td> <b> Default </b> 
     <td> <b>Description</b>
<tr> <td> USE_WEIGHTS  <td> Keyword <td> off 
     <td> Turn on correlated-sampling type reweighting
<tr> <td> MIXING  <td> Float <td> 0.95 <td> Mixing weight for energy contribution in mixed minimization
<tr> <td> EXTENDED_WFOUTPUT <td> Keyword <td>  off 
     <td> Turn on printout of wavefunction after each step of optimization into a different file
<tr> <td> MINFUNCTION  <td> String <td>  VARIANCE 
     <td> Choose the minimization function.  Options are:
 
VARIANCE (default) : \f$ \sum{(E_l - E_{ref})^2} \f$
 
ABSOLUTE : \f$ \sum{ | E_l - E_{ref} | } \f$
 
LORENTZ : \f$ \sum{ log(1+(E_l-E_{ref})^2/2) } \f$

ENERGY : \f$ \frac{1}{N} \sum { E_l }  \f$

MIXED : \f$ mixing \frac{1}{N} \sum { E_l } + (1-mixing) \sum{(E_l - E_{ref})^2}  \f$

For an energy minimization, it's advisable to also use USE_WEIGHTS, since
it's usually unstable otherwise.
</table>



*/
